5.2. Explain diabetes mellitus

This guide will help you answer 5.2. Explain diabetes mellitus.

Diabetes mellitus is a long-term health condition that affects how the body regulates blood sugar (glucose). It happens when your body cannot produce enough insulin, cannot use insulin properly, or both. Insulin is a hormone made by the pancreas that allows glucose from food to enter the body’s cells, giving them energy to function.

When a person has diabetes, their blood glucose levels can become too high. Over time, this can lead to serious health problems affecting the heart, kidneys, eyes, nerves, and more.

Types of Diabetes Mellitus

There are three main types of diabetes mellitus. Each type is different in cause, management, and effects. These types are:

1. Type 1 Diabetes
2. Type 2 Diabetes
3. Gestational Diabetes

Type 1 Diabetes

Type 1 diabetes is an autoimmune disorder. This means the body’s immune system attacks the insulin-producing cells in the pancreas by mistake. This stops the pancreas from making insulin.

Type 1 diabetes usually starts in childhood or adolescence but can develop at any age. People with this type depend on regular insulin injections or an insulin pump for life.

Symptoms of type 1 diabetes develop quickly and may include:

• Extreme thirst
• Frequent urination
• Weight loss despite eating more
• Fatigue (feeling very tired)
• Blurry vision

Without treatment, type 1 diabetes is life-threatening. Blood glucose levels must be carefully monitored, and insulin therapy (artificial insulin) is required to maintain healthy levels. Diet and lifestyle changes also play an important part in managing the condition.

Type 2 Diabetes

Type 2 diabetes is the most common form and typically develops in adults over 40, but it’s now being seen in younger people due to lifestyle changes. Unlike type 1, the pancreas still produces insulin in type 2 diabetes, but it doesn’t work effectively (known as insulin resistance). Alternatively, the pancreas may not produce enough insulin.

Type 2 diabetes is closely linked to lifestyle factors, such as:

• Being overweight or obese
• Physical inactivity
• Poor diet, especially diets high in sugar and fat

Symptoms for type 2 diabetes often develop slowly and may include:

• Tiredness
• Increased thirst and frequent urination
• Cuts or wounds taking a long time to heal
• Blurred vision
• Tingling or numbness in the fingers and toes

Managing type 2 diabetes can involve improving diet and exercise, taking medications to lower blood glucose, or occasionally insulin injections. Early diagnosis is important to prevent complications.

Gestational Diabetes

Gestational diabetes is a temporary form of diabetes that occurs during pregnancy. It happens when hormonal changes interfere with the body’s ability to use insulin effectively, leading to high blood sugar levels.

Pregnant women may not notice any symptoms, so screening during pregnancy is important. Risk factors for gestational diabetes include being overweight, having a family history of diabetes, or being of South Asian, Black African, or Caribbean ethnicity.

Gestational diabetes usually disappears after childbirth, but it can increase the risk of developing type 2 diabetes later in life for both the mother and the child.

How Does Diabetes Affect the Body?

High blood glucose levels can damage different parts of the body over time. Some of the key areas affected by diabetes include:

• Heart and blood vessels – Diabetes increases the risk of heart disease and stroke by damaging blood vessels.
• Eyes – High blood sugar can damage the retina (diabetic retinopathy), potentially leading to blindness if untreated.
• Kidneys – The condition can lead to kidney disease as the filtration function becomes damaged. This is called diabetic nephropathy.
• Nerves – High glucose can harm nerves, particularly in the hands and feet, causing pain or loss of sensation (diabetic neuropathy).
• Feet and skin – Reduced blood flow and sensation in the feet increase the risk of ulcers and infections.

Preventing Complications

While diabetes cannot always be cured, careful management can prevent or delay complications. People with diabetes should:

• Monitor blood sugar levels regularly.
• Stay physically active to help control blood glucose.
• Follow a healthy eating plan low in sugar, fat, and processed foods.
• Avoid smoking and excessive alcohol use.
• Attend regular check-ups with healthcare professionals.

Risk Factors for Developing Diabetes

Certain factors increase the likelihood of developing type 2 diabetes or gestational diabetes. These include:

• Family history of diabetes
• Being overweight or obese
• A sedentary lifestyle (not being physically active)
• Being over the age of 40 (or 25 for some ethnic groups)
• Having high blood pressure or high cholesterol
• Belonging to ethnic groups such as South Asian, Black African, or Caribbean

Diagnosis of Diabetes

A diagnosis of diabetes is usually confirmed through blood tests. These include:

• Fasting blood glucose test – Measures blood sugar levels after fasting (not eating) overnight.
• HbA1c test – Reflects average blood sugar levels over the previous 2–3 months.
• Oral glucose tolerance test (OGTT) – Evaluates the body’s response to a sugary drink.

If blood glucose levels are consistently high, diabetes is confirmed.

Treatment of Diabetes

Treatment depends on the type of diabetes.

• For type 1 diabetes, insulin therapy is the main treatment. Patients inject insulin or use an insulin pump to maintain blood glucose levels.
• For type 2 diabetes, treatment often starts with lifestyle changes such as improving diet and exercise. If needed, medication in tablet form (e.g., metformin) may be added. Some cases may require insulin later on.
• For gestational diabetes, diet and regular exercise can often manage blood sugar. In some cases, insulin or medication may be prescribed during pregnancy.

Complications of Untreated Diabetes

If left untreated, diabetes can cause life-altering complications. These include:

• Hypoglycaemia – Dangerously low blood sugar levels that may cause fainting or seizures.
• Heart disease – Increased risk of heart attacks and strokes.
• Kidney failure – Requiring dialysis or kidney transplant in severe cases.
• Blindness – Due to damage to the retina (diabetic retinopathy).
• Amputations – Severe infections or ulcers on the feet may require amputation.

Every person with diabetes is different, and the condition requires individualised management to suit their needs.

Final Thoughts

With appropriate care, most people with diabetes can live a full life. Education about the condition is key for making informed choices. Diabetes UK and other charities offer resources, advice, and support.

Lifestyle changes such as healthy eating, staying active, and reducing stress make a big difference. Many people also use technology, like glucose monitoring devices, to keep better control of their blood sugar.

Open communication with healthcare providers gives people with diabetes the confidence to manage their condition effectively. Early detection and good self-care help prevent complications and maintain a good quality of life.